Paying close attention to what your opponents are doing is a big part of learning Rummy. You can learn about their tactics and possible melds by keeping an eye on the cards they draw & discard. For example,lucky rummy if an opponent keeps drawing cards from the discard pile, it can mean they are trying to finish a particular run or set. On the other hand, if they are regularly discarding particular suits or ranks, it might indicate that they are not pursuing those combinations, which would let you modify your approach. Gaining insight into the psychology of your opponents' moves can also give you an advantage in combat.